"After age 30, most men begin to experience a gradual decline in testosterone," says David Samadi, MD, chairman of the urology department at Lenox Hill Hospital in nyc.

Although testosterone levels never reach zero (as estrogen levels do in women during menopause), low testosterone levels men to experience symptoms such as fatigue, low sex drive, and reduction of muscle mass.

While low testosterone is more prevalent in older men, it can occur in younger guys as well. Luckily, all of the causes of low testosterone in young guys are treatable, so in the event that you experience these symptoms at any age, there is no reason to ignore it.

Causes of Low Testosterone in Younger Men

For younger guys, a drop in testosterone levels may be caused by some ailments, such as type 2 diabetes, diabetes, chronic liver or kidney disease, COPD or other lung disorder, or pituitary gland issues, according to Dr. Samadi.

Genetic causes of low testosterone in males include the ailments Klinefelter syndrome, Kallmann syndrome, Prader-Willi syndrome, and Myotonic dystrophy. Another disease that could cause low testosterone is hemochromatosis, which makes the body shop too much iron.

"Low testosterone can also result when something happens, like trauma or steroid use, that prevents the testes from making the hormone," says Bruce Gilbert, MD, PhD, an adjunct clinical professor of urology and reproductive medicine at Weill Cornell Medical College and director of reproductive and sexual medicine in the Smith Institute for Urology of the North Shore-LIJ Health System.

Other causes of low testosterone in males younger than 50 include pituitary gland tumors, HIV infection, and radiation therapy or chemotherapy for cancer.

Doctors categorize causes of low testosterone as primary or secondary.

"Primary hypogonadism stems from a problem in the testicles," Samadi states. In secondary hypogonadism, the testicles are normal but function improperly because of a problem with the hypothalamus or pituitary gland."

Not everyone with low testosterone needs treatment. "When it comes to treating low testosterone in older men, we generally reserve treatment for people who have symptoms, such as tiredness and reduced libido," Gilbert says.

Such testosterone supplements come in the form of a gel, injections, patches, long-acting pellets, or oral inserts.

In these circumstances,"treatments are usually used only in the brief term, and if a physician has close monitoring and knowledge of the patient," Gilbert says.

An important consideration for younger men before getting treatment is fertility. "You do not want to offer supplemental testosterone to guys who want to be fertile since it can turn off sperm production," Gilbert says.

Once a young man goes off testosterone supplementation, there's a chance his sperm count will never return to what it was before he started. "Hence, men of reproductive age should think about alternatives which may improve their testosterone in addition to preserve their sperm production," he says. One such choice is a category of drugs known as selective estrogen receptor modulators (SERMs).

Other treatments for low testosterone include weight loss and other lifestyle changes, such as eating healthier and raising exercise.

The main point, however, is that in the event that you've got low testosterone symptoms, it's important to see your doctor. Then, your doctor can rule out potentially more serious causes of your symptoms, including hypertension or a thyroid problem, and give treatment that could improve your energy and quality of life.